Month: July 2021

在「Towards Inserting One Billion Rows in SQLite Under A Minute」這邊看到作者想要在一分鐘內在 MBP 2019 上面寫 1B 筆資料進 SQLite，裡面有些方法還蠻值得玩一下的，這台 MBP 2019 機器的規格是：

The machine I am using is MacBook Pro, 2019 (2.4 GHz Quad Core i5, 8GB, 256GB SSD, Big Sur 11.1)

第一版是 Python 寫的，塞 10M 筆花了 15 分鐘：

In this script, I tried to insert 10M rows, one by one, in a for loop. This version took close to 15 minutes, sparked my curiosity and made me explore further to reduce the time.

加了五個 PRAGMA 的版本變成 100M 筆十分鐘：

The naive for loop version took about 10 minutes to insert 100M rows.

用批次處理則可以降到八分半：

The batched version took about 8.5 minutes to insert 100M rows.

再來是拿經典神器 PyPy 出來用，降到兩分半：

All I had to do was run my existing code, without any change, using PyPy. It worked and the speed bump was phenomenal. The batched version took only 2.5 minutes to insert 100M rows. I got close to 3.5x speed :)

接下來就是跳槽到 Rust 了，中間也有不少 tuning 相關的討論，但直接先跳到最後面好了... 最後 100M 只用了 33 秒：

I created a threaded version, where I had one writer thread that received data from a channel and four other threads which pushed data to the channel. This is the current best version which took about 32.37 seconds.

能用 PyPy 的地方還是可以考慮一下的...